For many Louisvillians, the first snow of the year is ever so exciting. Even more exciting, though, is the snow later in the season that closes the city for a week. Having multiple days without school, being able to walk down the middle of the street because there are no cars, sledding, and sheltering at home on the couch are some of the most winter things that always feel like such an exciting treat. I am the biggest fan of snow, and I miss the mountains constantly; to me, snow is so much more than just a day off of school. I love the intricacies of a single snowflake and knowing what types of snow are best for snowmen and which are best for skiing. So I thought that since we’re all stuck inside, it’d be fun to learn a little more about the thing that caused the city’s frenzy. Although the general classifications of snow are along the lines of dry snow, powder, and slush, snow actually has very specific classifications. Although there is no “official” system for the classifications, there are some distinct categories that are often used to delegate the over 100 specific shapes of snowflakes. Although, as the common phrase states, “no two snowflakes are alike,” many of those unique snowflakes can fit into these categories.

Plate crystals

Plate crystals are flat, six-sided crystals, and they often have intricate patterns. Their temperature range is around 14-21℉. A smaller category within this one is what are called stellar dendrites. They are slightly more specific, although they carry many of the same shapes, stellar dendrites form in what is called the “dendritic growth zone,” which often has very high humidity levels that help the branches of the snowflake grow rapidly, giving them that quintessential snowflake shape. 

Needle crystals 

These snow crystals are long and slender and often look like tiny bits of white hair on your clothes. They often live in warmer, but still below freezing, temperatures, around 23-25℉.

Columnar crystals

These snowflakes are small, six-sided, rod or needle-shaped flakes. They can either be solid or hollow. The flakes with hollow columns have conical regions on the ends. They often form in colder temperatures than needed, around 14-25℉.

Capped columns

These flakes form when a crystal begins to form as a column crystal and then moves into the “dendritic growth zone,” which causes it to grow similar to a plane crystal, which favors plate-like growth. It becomes a column crystal with hexagonal plates on one or both ends. This form is known as a “capped column.”

Aggregation of snow crystals

This term refers to clusters of multiple individual snow crystals that have collided and stuck together while falling. What often seems to be one “snowflake” falling from the sky is most often a group, or aggregation, of many individual snowflakes.

Rimed snow crystals

These snow crystals are flakes coated with tiny, frozen, supercooled water droplets — called rime — which can obscure the original crystal shape if heavily rimed, forming a soft, spherical particle, which is known to many as graupel. These small flakes often bounce when they hit the ground and look like small styrofoam pieces.

Germs of ice crystals

These are the initial ice crystals. They are minute, less than 0.1 millimeters in size, and are what larger snowflakes grow from. They often take simple forms, like tiny columns or hexagonal plates, and they act as the nucleus, around which water vapor freezes to complete the snowflake.

Irregular snow particles

These are asymmetrical or broken snow particles, and they are often formed when crystals grow in a random fashion or when they break into pieces, often due to strong winds. They are considered quite a rare type in nature compared to the other, much more common classifications.